Slow release compositions comprising heterocyclic sulfonylurea herbicides, paraffin wax, hydrocarbon polymers, and particulate fillers

ABSTRACT

This invention relates to slow release granular compositions comprising one or more active herbicides and a process for their preparation.

BACKGROUND OF THE INVENTION

The invention relates to compositions comprising as the activeingredient one or more herbicides which are slowly released from saidgranular compositions.

Controlled release pesticidal compositions offer several possibleadvantages over conventional compositions. They are often preferredbecause fewer pesticide applications to the crop are necessary.Controlled release compositions offer safety to the environment byreducing pesticide overuse and run-off or soil (translocation) leachinginto unwanted neighboring areas such as water ways and wells. They canalso offer safety to the crop in instances when large doses ofconventional formulations are phytotoxic and provide safety to workersapplying pesticides in the field by reducing the toxicity of thepesticide. Finally, controlled release compositions allow the effectiveuse of pesticides which are too rapidly degraded, volatilized or leachedaway by rain in conventional formulations (i.e., conventional pesticideswith very low residual activity).

JP Hei 2[1990]-288,803 discloses a release-controlled granule containinga sulfonylurea, a barnyardgrass herbicide, a clay mineral, a paraffinwax and a surfactant.

SUMMARY OF THE INVENTION

This invention relates to a slow release herbicidal particulatecomposition comprising:

(1) One or more active ingredients selected from the group:

(i)N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-1-methyl-4-(2-methyl-2H-tetrazole-5-yl)-1H-pyrazole-5-sulfonamide[Compound I];

(ii) methyl2-[[[[[4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]methyl]benzoate[Compound II or Londax® herbicide]; and

(iii) ethyl5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate[Compound III];

(2) paraffin wax;

(3) synthetic or naturally occurring hydrocarbon polymer(s);

(4) a solid particulate filler; and

(5) optionally, an adjuvant such as a surfactant or dispersant; whereinthe weight ratio of paraffin wax: hydrocarbon polymer ranges from 5:1;to 0.5:1; the weight ratio of active ingredient(s): paraffin wax andhydrocarbon polymer ranges from 1:25 to 1:0.25 and the filler rangesfrom 1 to 95% by weight of the total composition.

The adjuvants such as surfactants and dispersants are to adjust therelease rate. The filler may include one or more fillers.

The particulate compositions of this invention can be used alone tocontrol undesired vegetation. The particulate compositions of thisinvention are also useful in preparing granular compositions containingin addition other herbicidally active compounds with adjuvants known tobe needed to prepare the granular compositions. The particulatecompositions of this invention are preferably useful in the preparationof a granular composition for the control of weeds in rice comprisingthe present particulates, a herbicide useful for control ofbarnyardgrass and adjuvants.

Non-limiting examples of synthetic or naturally occurring polymers ofthe composition of the invention include ethylene/vinyl acetatecopolymers (such as Elvax®) or oxidized polyethylene polymer (such asEpolene® E-10).

What is meant by solid particulate filler is any solid particles of 50microns maximum, preferably below 25 microns, in particle size, examplesof which include clay, calcium carbonate, calcium sulfate, calciumphosphate, barium sulfate, diatamaceous earth, talc and bentonite.

The size of the particles of the active ingredient is in the same sizerange given for the solid particulate filler.

Non-limiting examples of paraffin waxes of the composition of theinvention include petroleum-type solid paraffin waxes, and crystallinecompositions containing normal paraffin compounds and C₁₈ -C₃₆isoalkanes and cycloalkanes.

The compositions of the invention which are preferred for their ease ofpreparation and/or biological activity are:

(1) Compositions wherein the active ingredient is selected from theabove Compounds I, II and III and the ratio of paraffin wax:hydrocarbonpolymer ranges from 4:1 to 0.5:1;

(2) The composition of Preferred 1 wherein the ratio of activeingredient(s):paraffin wax/hydrocarbon polymer ranges from 1:10 to 1:2;

(3) The composition of Preferred 2 wherein the polymer isethylene/vinylacetate copolymer or oxidized polyethylene;

(4) The composition of Preferred 3 wherein a surfactant is used;

(5) The composition of Preferred 4 wherein the filler is calciumcarbonate.

This invention also relates to a process for preparing slow releasepesticidal compositions wherein appropriate amounts of the activeingredient, paraffin wax and the polymer are mixed and heated to60°-120° C., preferably 80°-100° C., and then the solid particulatefiller is added, followed by cooling with agitation to room temperatureto form a particulate. The resulting particulate composition may beapplied directly or may be optionally mixed with other compositionsknown in the art containing one or more additional active ingredientfollowed by extrusion to prepare granules. The controlled releaseparticulates can also be used to make other types of agriculturalformulations such as liquid flowable products.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to particulate controlled release herbicidecompositions for use in rice paddy fields for control of weeds. Thesenovel compositions consist of:

1. A herbicide or mixture of herbicides;

2. Paraffin wax;

3. At least one higher melting polyhydrocarbon compatible with the waxabove;

4. A solid particulate filler; and

5. Optionally, an adjuvant such as a surfactant or dispersant to adjustthe release rate.

Various additional adjuvants can be used in quantities under 5% of theweight of the controlled release composition to adjust the releasecharacteristics. In general, inorganic bases such as magnesium hydroxideand other water-soluble organic or inorganic particulates such as sugarstend to accelerate release. Water-soluble starches and polyacrylamidestend to make the release profile more linear with time as well asincrease the release rate. Hydrophobic or oleophilic compounds such asstearic acid and stearates generally greatly reduce the release rate.

Although the particulate compositions of this invention are useful inparticulate form they are also useful to prepare granular formulationsby the further addition of porous or nonporous solid material, examplesof which include sand, aggregated clays such as kaolinite, bentonite andattapulgite, vermiculite and granular salts or organic compounds such assugars, urea, potassium or calcium carbonate, ammonium nitrate and othergranular fertilizers and many inorganic salts. The present particulatesmay also be used to prepare granular formulations that also includeswater-dispersible granules containing active ingredients, examples ofwhich are Glean® 75DF, Pinnacle® DF and Londax® 60 DF, products of E. I.du Pont de Nemours and Company, Wilmington, Del. Preferred granule sizeis about 150 to 4000 microns with 250 to 2000 microns being morepreferred.

Two general granular products can be prepared from the particulatecompositions of this invention. The process involves:

1. Granulating the compositions preferably in admixture with otheractives and adjuvants such as dispersants and surfactants by knownprocesses;

2. Overcoating the granular solids with a controlled release activeparticulate, using a binder.

The controlled release particulates could be used to prepare granularproducts containing complimentary pesticides also in controlled releaseform or as free or unencapsulated form, e.g., insecticides, fungicidesor other herbicides. An especially valuable product was made involvingcommercial Londax® (Du Pont), widely used to control weeds in rice, saidproduct containing Compound II as the active ingredient and a controlledrelease particulate of Compound I. Compound is a complimentarysulfonylurea compound that is more efficacious than Compound II againstperennial weeds, e.g., (Cyperus) and grasses found in rice paddy fields,and therefore provides a broader range of weed control than Compound IIalone. However, in some geographic locations and climatic conditions,rice plants can be injured by Compound I. The major beneficial effectsof the controlled released treatment of Compound I was to prolong itsactivity and reduce its phytotoxicity to the rice plants. Non-limitingexamples of other suitable pesticides are listed below. The controlledrelease particulates of this invention consist of the pesticide in aprotective matrix consisting of the aforementioned combination of aparaffin wax, hydrocarbon polymer and solid particulate filler. Thepreferred maximum particle size of the particulates of the invention is420 microns, obtained by passing through a 35 mesh screen. The preferredmaximum size for direct application or use in preparing of formulations,where suspendability in a liquid medium is required, is 25 microns.Reduction of particle size, if required, can be carried out byconventional milling techniques. In practice, however, the process ofthis invention produces controlled particulates primarily in the desiredsize range of 50 to 420 microns without milling.

Use of the polyhydrocarbon component in conjunction with paraffin waxconfers much improved toughness and resistance to deformation by heat.Also, controlled release particulates using the components describedabove except for omission of such polymers tend to agglomerate at 50° C.during long term storage whereas similar compositions prepared with abarrier system containing 50% each of paraffin wax and a low molecularweight oxidized polyethylene (Eastman Kodak's Epolene® E-10), forexample, generally show no aggregation under such conditions.

The present slow release herbicidal particulate compositions areadvantageous over slow release compositions of the art in that the formresulting from the present process is a particulate, not a granule. Itis therefore not necessary to grind or mill the present compositions tothe size needed in order to mix the ingredients with any desiredadditional ingredients that would or would not be subject to slowrelease. The compositions of the present invention advantageously can beused as a herbicide in particulate form or it can be granulated to formformulations that are totally in controlled release form or formulationshaving controlled release particulates of the invention with free orunencapsulated active ingredients.

The particulates of the present invention are further advantageousbecause they are physically stronger than prior art particulates and arebetter resistant to elevated temperatures without change in the releaserate. The present slow release herbicidal particulate compositions arenot possible without the inclusion of the hydrocarbon polymer. The useof wax alone without the hydrocarbon polymer does not usually produce aparticulate. The absence of the solid particulate filler will notproduce the particulates of the invention because of the agglomeration.

    __________________________________________________________________________    Common Name                                                                             Chemical Name                                                       __________________________________________________________________________    acetochlor                                                                              2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide       acifluorfen                                                                             5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid         aclonifen 2-chloro-6-nitro-3-phenoxybenzenamine                               acrolein  2-propenal                                                          alachlor  2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide           alloxydim methyl 2,2-dimethyl-4,6-dioxo-5-[1-[(2-propenyloxy)amino]butylid              ene]cyclohexanecarboxylate                                          ametryn   N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-dia              mine                                                                amitrole  1H-1,2,4-triazol-3-amine                                            AMS       ammonium sulfamate                                                  anilofos  S-[2-[(4-chlorophenyl)(1-methylethyl)amino]-2-oxoethyl]                       O,O-dimethylphosphorodithioate                                      asulam    methyl [(4-aminophenyl)sulfonyl]carbamate                           atrazine  6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine      aziprotryne                                                                             4-azido-N-(1-methylethyl)-6-methylthio-1,3,5-triazin-2-amine        azoluron  N-(1-ethyl-1H-pyrazol-5-yl)-N'-phenylurea                           barban    4-chloro-2-butynyl 3-chlorocarbamate                                benazolin 4-chloro-2-oxo-3(2H)-benzothiazole acetic acid                      benfluralin                                                                             N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine          bensulfuron                                                                             2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]methylcarbonyl]amino]s              ulfonyl]methyl]benzoic acid, methyl ester                           bensulide O,O-bis(1-methylethyl) S-[2-[(phenylsulfonyl)amino]-ethyl]phosph              orodithioate                                                        bentazon  3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)one,2,2-dioxid              e                                                                   benzofluor                                                                              N-[4-(ethylthio)-2-(trifluoromethyl)phenyl]methanesulfonamide       benzoylprop                                                                             N-benzoyl-N-(3,4-dichlorophenyl)-DL-alanine                         benzthiazuron                                                                           N-2-benzothiazolyl-N'-methylurea                                    bialaphos 4-(hydroxymethylphosphinyl)-L-2-aminobutanoyl-L-alanyl-L-alanine              5                                                                   bifenox   methyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate                      bromacil  5-bromo-6-methyl-3-(1-methylpropyl)-2,4(1H,3H)pyrimidinedione       *bromobutide                                                                            (+)2-bromo-3,3-dimethyl-N-(1-methyl-1-phenylethyl)butanamide        bromofenoxim                                                                            3,5-dibromo-4-hydroxybenzaldhyde O-(2,4-dinitrophenyl)oxime         bromoxynil                                                                              3,5-dibromo-4-hydroxybenzonitrile                                   bromuron  N'-(4-bromophenyl)-N,N-dimethylurea                                 buminafos dibutyl [1-(butylamino)cyclohexyl]phosphonate                       butachlor N-(butoxymethyl)-2-chloro-N-(2,6-diethylphenyl)acetamide            butamifos O-ethyl O-(5-methyl-2-nitrophenyl)-(1-methylpropyl)phosphoramido              thioate                                                             buthidazole                                                                             3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-meth              yl-2-imidazolidinone                                                butralin  4-(1,1-dimethylethyl)-N-(1-methylpropyl)-2,6-dinitrobenzenamine     butylate  S-ethyl bis(2-methylpropyl)carbamothioate                           cacodylic acid                                                                          dimethyl arsinic oxide                                              carbetamide                                                                             (R)-N-ethyl-2-[[(phenylamino)carbonyl]oxy]-propanamide              CDAA      2-chloro-N,N-di-2-propenylacetamide                                 CDEC      2-chloroallyl diethyldithiocarbamate                                chlomethoxyfen                                                                          4-(2,4-dichlorophenoxy)-2-methoxy-1-nitrobenzene                    chloramben                                                                              3-amino-2,5-dichlorobenzoic acid                                    chlorbromuron                                                                           3-(4-bromo-3-chlorophenyl)-1-methoxy-1-methylurea                   chlorbufam                                                                              1-methyl-2-propynl(3-chlorophenyl)carbamate                         chlorfenac                                                                              2,3,6-trichlorobenzeneacetic acid                                   chlorflurecol                                                                           methyl 2-chloro-9-hydroxy-9H-fluorene-9-carboxylate                 methyl                                                                        chloridazon                                                                             5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone                        chlorimuron                                                                             2-[[[[(4-chloro-6-methoxy-2-pyrimidinyl)-ethylamino]-carbonyl]am              ino]sulfonyl]benzoicacid, ethyl ester                               chlornitrofen                                                                           1,3,5-trichloro-2-(4-nitrophenoxy)benzene                           chloropicrin                                                                            trichloronitromethane                                               chloroxuron                                                                             N'-[4-(4-chlorophenoxy)phenyl]-N,N-dimethylurea                     chlorpropham                                                                            1-methylethyl 3-chlorophenylcarbamate                               chlorsulfuron                                                                           2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbon              yl]benzenesulfonamide                                               chlorthal-                                                                              dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate               dimethyl                                                                      chlorthiamid                                                                            2,6-dichlorobenzene carbothioamide                                  chlortoluron                                                                            N'-(3-chloro-4-methylphenyl)-N,N-dimethylurea                       cinmethylin                                                                             exo-1-methyl-4-(1-methylethyl)-2-[(2-methylphenyl)methoxy]-7-oxa              bicyclo-[2.2.1]  heptane                                            clethodim (E,E)-(+)-2-[1-[[(3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(et              hylthio)propyl]-3-hydroxy-2-cyclohexen-1-one                        clomazone 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone           cloproxydim                                                                             (E,E)-2-[1-[[(3-chloro-2-propenyl)oxy)imino]-butyl]-5-[2-(ethylt              hio)propyl]-3-hydroxy-2-cyclohexen-1-one                            clopyralid                                                                              3,6-dichloro-2-pyridinecarboxylic acid                              CMA       calcium salt of MAA                                                 cyanazine 2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpr              opanenitrile                                                        cycloate  S-ethyl cyclohexylethylcarbamothioate                               cycloxydim                                                                              2-[1-ethoxyimino)butyl]-3-hydroxy-5-(tetrahydro-2H-thiopyran-3-y              l)-2-cyclohexene-1-one                                              cycluron  3-cyclooctyl-1,1-dimethylurea                                       cyperquat 1-methyl-4-phenylpyridinium                                         cyprazine 2-chloro-4-(cyclopropylamino)-6-(isopropylamino)-s-triazine         cyprazole N-[5-(2-chloro-1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]cyclopro              panecarboxamide                                                     cypromid  3',4'-dichlorocyclopropanecarboxanilide                             dalapon   2,2-dichloropropanoic acid                                          dazomet   tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione               DCPA      dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate               desmedipham                                                                             ethyl [3-[[(phenylamino)carbonyl]oxy]phenyl]-carbamate                        (methylthio)-s-triazine                                             diallate  S-(2,3-dichloro-2-propenyl)bis(1-methylethyl)-carbamothioate        dicamba   3,6-dichloro-2-methoxybenzoic acid                                  dichlobenil                                                                             2,6-dichlorobenzonitrile                                            dichlorprop                                                                             (+)-2-(2,4-dichlorophenoxy)propanoic acid                           *diclofopmethyl                                                                         (+)-2-[4-(2,4-dichlorophenoxy)phenoxy]propanoic acid, methyl                  ester                                                               diethatyl N-(chloroacetyl)-N-(2,6-diethylphenyl)glycine                       difenoxuron                                                                             N'-[4-(4-methoxyphenoxy)phenyl]-N,N-dimethylurea                    difenzoquat                                                                             1,2-dimethyl-3,5-diphenyl-1H-pyrazolium ion                         diflufenican                                                                            N-(2,4-difluorophenyl)-2-(3-trifluoromethylphenoxy)pyridine-3-ca              rboxamide                                                           dimefuron N'-[3-chloro-4-[5-(1,1-dimethylethyl)-2-oxo-1,3,4-oxadiazol-3(2H              )-yl]phenyl]-N,N-dimethylurea                                       dimethachlor                                                                            2-chloro-N-(2,6-dimethylphenyl)-N-(2-methoxyethyl)acetamide         dimethametryn                                                                           N-(1,2-dimethylpropyl)-N'-ethyl-6-(methylthio)-1,3,5-triazine-2,              4-diamine                                                           dimethipin                                                                              2,3-dihydro-5,6-dimethyl-1,4-dithiin1,-1,4,4-tetraoxide             dimethylarsinic                                                                         dimethylarsinic acid                                                dinitramine                                                                             N.sub.3,N.sub.3 -diethyl-2,4-dinitro-6-(trifluoromethyl)-1,3-ben              zenediamine                                                         dinoseb   2-(1-methylpropyl)-4,6-dinitrophenol                                dinoterb  2-(1,1-dimethylethyl)-4,6-dinitrophenol                             diphenamid                                                                              N,N-dimethyl-α-phenylbenzeneacetamide                         dipropetryn                                                                             6-(ethylthio)-N,N'-bis(1-methylethyl)-1,3,5-triazine-2,4-diamine    diquat    6,7-dihydrodipyrido[1,2-a:2',1'-c]pyrazinediium ion                 diuron    N'-(3,4-dichlorophenyl)-N,N-dimethylurea                            DNOC      2-methyl-4,6-dinitrophenol                                          DPX-V9360 2-[[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]aminosulfonyl]-N,              N-dimethyl 3-pyridinecarboxamide                                    DSMA      disodium salt of MAA                                                dymron    N-(4-methylphenyl)-N'-(1-methyl-1-phenylethyl)urea                  eglinazine-ethyl                                                                        N-[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]glycine ethyl                   ester                                                               endothall 7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid                    EPTC      S-ethyl dipropylcarbamothioate                                      ethalfluralin                                                                           N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl)b              enzenamine                                                          ethidimuron                                                                             N-[5-(ethylsulfonyl)-1,3,4-thiadiazol-2-yl]-N,N'-dimethylurea       *ethofumesate                                                                           (+)-2-ethoxy-2,3-dihydro-3,3-dimethyl5-benzofuranylmethanesulfon              ate                                                                 fenac     2,3,6-trichlorobenzeneacetic acid                                   *fenoprop (+)-2-(2,4,5-trichlorophenoxy)propanoic acid                        *fenoxaprop                                                                             (+)-2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoic acid       fenuron   N,N-dimethyl-N'-phenylurea                                          fenuron TCA                                                                             Salt of fenuron and TCA                                             flamprop-M                                                                              1-methylethyl N-benzoyl-N-(3-chloro-4-fluorophenyl)-D-alanine       isopropyl                                                                     flamprop-methyl                                                                         methyl N-benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alaninate           *fluazifop                                                                              (+)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic               acid                                                               fluazifop-P                                                                             (R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]  oxy]phenoxy]propano              ic acid                                                             fluchloralin                                                                            N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)benzen              amine                                                               flumeturon                                                                              N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl]urea                     fluralin  N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine          fluorodifen                                                                             p-nitrophenyl α,α,α-trifluoro-2-nitro-p-tolyl               ether                                                               fluoroglycofen                                                                          carboxymethyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitroben              zoate                                                               flurecol-butyl                                                                          butyl 9-hydroxy-9H-fluorene-9-carboxylate                           fluridone 1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone    flurochloridone                                                                         3-chloro-4-(chloromethyl)-1-[3-(trifluoromethyl)phenyl]-2-pyrrol              idinone                                                             fluroxypyr                                                                              [(4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxy]acetic acid         fomesafen 5-[2-chloro-4-(trifluoromethyl)phenoxy]-N-(methylsulfonyl)-2-nit              robenzamide                                                         fosamine- ethyl hydrogen (aminocarbonyl)phosphonate                           ammonium  ammonium ethyl                                                      glufosinate-                                                                            ammonium 2-amino-4-(hydroxymethylphosphinyl)butanoate               ammonium                                                                      glyphosate                                                                              N-(phosphonomethyl)glycine                                          haloxyfop 2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]prop              anoic acid                                                          hexaflurate                                                                             potassium hexafluoroarsenate                                        hexazinone                                                                              3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H              )dione                                                              imazamethabenz                                                                          6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-m-toluic acid,               methyl ester and 6-(4-isopropyl-4-methyl-                                     5-oxo-2-imidazolin-2-yl)-p-toluic acid, methyl ester                imazapyr  (+)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-              2-yl]-3-pyridine-carboxylic acid                                    imazaquin 2-[4,5-dihydro-4-methyl-4-(1-methylethyl-5-oxo-1H-imidazol-2-yl]              -3quinoline-carboxylic acid                                         imazethapyr                                                                             (+)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-              2-yl]-5-ethyl-3-pyridinecarboxylic acid                             ioxynil   4-hydroxy-3,5-diiodobenzonitrile                                    isocarbamid                                                                             N-(2-methylpropyl)-2-oxo-1-imidazolidinecarboxamide                 isopropalin                                                                             4-(1-methylethyl)-2,6-dinitro-N,N-dipropylbenzenamine               isoproturon                                                                             N-(4-isopropylphenyl)-N'  ,N'-dimethylurea                          isouron   N'-[5-(1,1-dimethylethyl)-3-isoxazolyl]-N,N-dimethylurea            isoxaben  N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzami              de                                                                  karbutilate                                                                             3-[[(dimethylamino)carbonyl]amino]phenyl-(1,1-dimethylethyl)carb              amate                                                               lactofen  (+)-2-ethoxy-1-methyl-2-oxoethyl 5-[2-chloro-4-(trifluoromethyl)              phenoxy]-2-nitrobenzoate                                            lenacil   3-cyclohexyl-6,7-dihydro-1H-cyclopenta-pyrimidine-2,4(3H,5H)-dio              ne                                                                  linuron   N'-(3,4-dichlorophenyl)-N-methoxy-N-methylurea                      MAA       methylarsonic acid                                                  MAMA      monoammonium salt of MAA                                            MCPA      (4-chloro-2-methylphenoxy)acetic acid                               MCPA-thioethyl                                                                          S-ethyl (4-chloro-2-methylphenoxy)ethanethioate                     MCPB      4-(4-chloro-2-methylphenoxy)butanoic acid                           mecoprop  (+)-2-(4-chloro-2-methylphenoxy)propanoic acid                      mefenacet 2-(2-benzothiazolyloxy)-N-methyl-N-phenyl acetamide                 mefluidide                                                                              N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]aceta              mide                                                                metamitron                                                                              4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one                   metazachlor                                                                             2-chloro-N-(2,6-dimethylphenyl)-N-(1(H)-pyrazol-1-ylmethyl)aceta              mide                                                                methabenz-                                                                              1,3-dimethyl-3-(2-benzothiazolyl)urea                               thiazuron                                                                     methal-   N-(2-methyl-2-propenyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)              benzenamide                                                         propalin                                                                      metham    methylcarbamodithioic acid                                          methazole 2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione      methoxuron                                                                              N'-(3-chloro-4-methoxyphenyl)-N,N-dimethylurea                      methoxyphenone                                                                          (4-methoxy-3-methylphenyl)(3-methylphenyl)methanone                 methyldymron                                                                            N-methyl-N'-(1-methyl-1-phenylethyl)-N-phenylurea                   metobromuron                                                                            N'-(4-bromophenyl)-N-methoxy-N-methylurea                           metolachlor                                                                             2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)a              cetamide                                                            metoxuron N'-(3-chloro-4-methoxyphenyl)-N,N-dimethylurea                      metribuzin                                                                              4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)              -one                                                                metsulfuron                                                                             2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)methylamino]carbony              l]amino]sulfonyl]benzoic acid, methyl ester                         MH        1,2-dihydro-3,6-pyridazinedione                                     molinate  S-ethyl hexahydro-1H-azepine-1-carbothioate                         monalide  N-(4-chlorophenyl)-2,2-dimethylpentanamide                          monolinuron                                                                             3-(p-chlorophenyl)-1-methoxy-1-methylurea                           monuron   N'-(4-chlorophenyl)-N,N-dimethylurea                                MSMA      monosodium salt of MAA                                              naproanilide                                                                            2-(2-naphthalenyloxy)-N-phenylpropanamide                           napropamide                                                                             N,N-diethyl-2-(1-naphthalenyloxy)propanamide                        naptalam  2-[(1-naphthalenylamino)carbonyl]benzoic acid                       neburon   1-butyl-3-(3,4-dichlorophenyl)-1-methylurea                         nitralin  4-methylsulfonyl-2,6-dinitro-N,N-dipropylaniline                    nitrofen  2,4-dichloro-1-(4-nitrophenoxy)benzene                              nitrofluorfen                                                                           2-chloro-1-(4-nitrophenoxy)-4-(trifluoromethyl)benzene              norea     N,N-dimethyl-N'-(octahydro-4,7-methano-1H-inden-5-yl)urea                     3aα,4α,5α,7α,7αa-isomer               norflurazon                                                                             4-chloro-5-(methylamino)-2-[3-(trifluoromethyl)phenyl]-3(2H)-pyr              idazinone                                                           orbencarb S-[2-(chlorophenyl)methyl]diethylcarbamothioate                     oryzalin  4-(dipropylamino)-3,5-dinitrobenzenesulfonamide                     oxadiazon 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-              1,3,4-oxadiazol-2(3H)-one                                           oxyfluorfen                                                                             2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene     paraquat  1,1'-dimethyl-4,4'-dipyridinium ion                                 pebulate  S-propyl butylethylcarbamothioate                                   pendimethalin                                                                           N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine               perfluidone                                                                             1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl]methanesulf              onamide                                                             phenisopham                                                                             3-[[(1-methylethoxy)carbonyl]amino]phenyl ethylphenylcarbamate      phenmedipham                                                                            3-[(methoxycarbonyl)amino]phenyl (3-methylphenyl)carbamate          picloram  4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid                   piperophos                                                                              S-[2-(2-methyl-1-piperidinyl)-2-oxoethyl]-O,O-dipropyl                        phosphorodithioate                                                  pretilachlor                                                                            2-chloro-N-(2,6-diethylphenyl)-N-(2-propoxyethyl)acetamide          procyazine                                                                              2-[[4-chloro-6-(cyclopropylamino)-1,3,5-triazine-2-yl]amino]-2-m              ethylpropanenitrile                                                 prodiamine                                                                              2,4-dinitro-N3,N3-dipropyl-6-(trifluoromethyl)-1,3-benzenediamin              e                                                                   profluralin                                                                             N-(cyclopropylmethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)be              nzenamine                                                           proglinazine-                                                                           N-[4-chloro-6-[(1-methylethyl)amino]-1,3,5-triazinethyl-2-yl]gly              cine ethyl ester                                                    ethyl                                                                         prometon  6-methoxy-N,N'-bis(1-methylethyl)-1,3,5-triazine-2,4-diamine        prometryn N,N'-bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamin              e                                                                   pronamide 3,5-dichloro-N-(1,1-dimethyl-2-propynyl)benzamide                   propachlor                                                                              2-chloro-N-(1-methylethyl)-N-phenyl-acetamide                       propanil  N-(3,4-dichlorophenyl)propanamide                                   propaquizafop                                                                           2-[[(1-methylethylidene)amino]oxy]ethyl 2-[4-[(6-chloro-2-quinox              alinyl)oxy]phenoxy]propanoate                                       propazine 6-chloro-N,N'-bis(1-methylethyl)-1,3,5-triazine-2,4-diamine         propham   1-methylethyl phenylcarbamate                                       propyzamide                                                                             3,5-dichloro-N-(1,1-dimethyl-2-propynl)benzamide                    prosulfalin                                                                             N-[[4-(dipropylamino)-3,5-dinitrophenyl]sulfonyl]-S,S-dimethylsu              lfilimine                                                           prosulfocarb                                                                            S-benzyldipropylthiocarbamate                                       prynachlor                                                                              2-chloro-N-(1-methyl-2-propynyl)acetanilide                         pyrazon   5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone                        pyrazosulfuron-                                                                         ethyl 5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]su              lfonyl]-1-methyl-1H-pyrazole-4-carboxylate                          ethyl                                                                         pyrazoxyfen                                                                             2-[[4-(2,4-dichlorobenzoyl)-1,3-dimethyl-1H-pyrazol-5-yl]oxy]-1-              phenylethanone                                                      pyridate  O-(6-chloro-3-phenyl-4-pyridazinyl) S-octylcarbonothioate           quizalofop                                                                              (+)-2-[4-[(6-chloro-2-quinoxalinyl)oxy]phenoxy]propanoic acid,                ethyl ester                                                         ethyl                                                                         secbumeton                                                                              N-ethyl-6-methoxy-N'-(1-methylpropyl)-1,3,5-triazine-2,4-diamine    sethoxydim                                                                              2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyc              lohexen-1-one                                                       siduron   N-(2-methylcyclohexyl)-N'-phenylurea                                simazine  6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine                    simetryn  N,N'-diethyl-6-(methylthio)-1,3,5-triazine-2,4-diamine              sodium chlorate                                                                         sodium chlorate                                                     sodium mono-                                                                            chloroacetic acid, sodium salt                                      chloroacetate                                                                 sulfometuron                                                                            2-[[[[(4,6-dimethyl-2-pyrimidinyl)amino]carbonyl]amino]                       sulfonyl]benzoic acid, methyl ester                                 methyl                                                                        2,4,5-T   (2,4,5-trichlorophenoxy)acetic acid                                 2,3,6-TBA 2,3,6-trichlorobenzoic acid                                         TCA       trichloroacetic acid                                                tebutam   2,2-dimethyl-N-(1-methylethyl)-N-(phenylmethyl)propanamide          tebuthiuron                                                                             N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N'-dimethylure              a                                                                   terbacil  5-chloro-3-(1,1-dimethylethyl)-6-methyl-2,4(1H,3H)pyrimidinedion              e                                                                   terbuchlor                                                                              N-(butoxymethyl)-2-chloro-N-[2-(1,1-dimethylethyl)-6-methylpheny              l]acetamide                                                         terbumeton                                                                              N-(1,1-dimethylethyl)-N'-ethyl-6-methoxy-1,3,5-triazine-2,4-diam              ine                                                                 terbuthylazine                                                                          2-(tert-butylamino)-4-chloro-6-(ethylamino)-s-triazine              terbutol  2,6-di-tert-butyl-p-tolyl methylcarbamate                           terbutryn N-(1,1-dimethylethyl)-N'-ethyl-6-(methylthio)-1,3,5-triazine-2,4              -diamine                                                            thifensulfuron                                                                          3-[[[[(4-methoxy-6-methyl-1,3,5,-triazin-2-yl)amino]carbonyl]ami              no]sulfonyl]-2-thiophenecarboxylic acid, methyl ester               thiameturon-                                                                            methyl 3-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbon              yl]amino]sulfonyl]2-thiophenecarboxylate                            methyl                                                                        thiazafluron                                                                            N,N'-dimethyl-N-[5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl]urea     thiobencarb                                                                             S-[(4-chlorophenyl)methyl] diethylcarbamothioate                    tiocarbazil                                                                             S-(phenylmethyl) bis(1-methylpropyl)carbamothioate                  tralkoxydim                                                                             2-[1-(ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-trimethylphenyl)-2-              cyclohexen-1-one                                                    triallate S-(2,3,3-trichloro-2-propenyl) bis(1-methylethyl)carbamothioate     triasulfuron                                                                            2-(2-chloroethoxy)-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)am              ino]carbonyl]benzenesulfonamide                                     tribenuron                                                                              2-[[[[N-(4-methoxy-6-methyl-1,3,5-triazine-2-yl)-N-methylamino]               carbonyl]amino]sulfonyl]benzoic acid, methyl ester                  methyl                                                                        triclopyr [(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid                      *tridiphane                                                                             (+)2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane           trietazine                                                                              6-chloro-N,N,N'-triethyl-1,3,5-triazine-2,4-diamine                 trifluralin                                                                             2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine             trimeturon                                                                              1-(p-chlorophenyl)-2,3,3-trimethylpseudourea                        2,4-D     (2,4-dichlorophenoxy)acetic acid                                    2,4-DB    4-(2,4-dichlorophenoxy)butanoic acid                                vernolate S-propyl dipropylcarbamothioate                                     xylachlor 2-chloro-N-(2,3-dimethylphenyl)-N-(1-methylethyl)acetamide          __________________________________________________________________________

In the preparation of the samples shown below, the active material andadditives were in a finely divided state, i.e., below 25 microns, andthey were milled, if necessary, to achieve this. After the encapsulationprocess, the products were screened through a 35 mesh screen (500microns). Most of the controlled release product was under 200 micronsin size.

In the analysis work conducted to determine the cumulative amount ofactive released from the sample, sufficient sample was placed in pH7buffered water to provide a total concentration of active of 30 partsper million. The aqueous mixtures were aged at room temperature.Aliquots were periodically taken which were filtered and the cumulativeamount of active present was determined by HPLC using unmodified activeas a control. Where the sulfonylurea was less soluble than 30 ppm, asmaller sample size was used, sufficient to provide a total of 2 ppmactive.

The invention is further illustrated by the following examples whereinall parts and percentages are by weight unless otherwise indicated.

EXAMPLE 1

A mixture of 0.5 g powderedN-[[(4,6-dimethoxy-2-pyrimidinyl)-amino]carbonyl]-1-methyl-4-(2-methyl-2H-tetrazole-5-yl)-1H-pyrazole-5-sulfonamide(Compound I) and 1.3 g of a 1:1 melt blend of paraffin wax and oxidizedpolyethylene (Epolene® E-10, Eastman Kodak Co.) were heated withagitation to 100° C. in a forced air oven. Then, 7.0 g of solidparticulate calcium phosphate (tribasio) which was preheated to 100° C.was added and the mixture was stirred until a homogenous mass resulted.Heating was discontinued and the mixture was stirred until roomtemperature was reached. The resultant particulate containing 5.6%active was screened through a 35 mesh screen and the release rate in pH7 water was measured. In 17 hours, the cumulative amount released was40%, in 136 hours, 65% was released and in 304 hours, 80% was released.

In simultaneous greenhouse tests, to determine the phytotoxicity ofCompound I to rice, the above controlled release showed a reduction indamage to rice plants up to 50% when compared with the unmodifiedCompound I. In this experiment, the Compound I controlled release sampleas well as unmodified Compound I were used at an application rate of 12g a.i./HA, in conjunction with Compound II applied at an applicationrate of 24 g a.i./HA.

EXAMPLE 2

Using the same process as described in (1), except for the use ofcalcium carbonate instead of calcium phosphate (tribasic), a powderedblend was made of 0.5 g Compound I, 0.7 g 1:1 paraffin wax: Epolene®E-10 and 2.0 calcium carbonate. The active content of Compound I was15.2%. In 19 hours, 18% of the active compound was released; in 164hours 61% was released, and in 331 hours 70% was released.

EXAMPLE 3

Using the procedure of Example 1, a particulate mixture of 0.5 gCompound I, 0.4 g paraffin wax, 0.4 g ethylene-vinyl acetate copolymer(Elvax® 210, E. I. du Pont de Nemours and Company) and 3.0 g calciumcarbonate was made. The product contained 11.62 g of the activecompound. The cumulative release observed was 19% of the active compoundin 17 hours, 55% in 113 hours and 79% in 304 hours.

EXAMPLE 4

Following the process of Example 1, except substituting a powderedurea-formaldehyde fertilizer for the mineral filler, a slow releasecomposition was made in which the substrate has nutritive value and isbiodegradable. The mixture consisted of 0.5 g Compound I, 0.4 g paraffinwax, 0.4 g Epolene® E-10 and 3.0 g powdered urea-formaldehyde polymer.The urea-formaldehyde powdered polymer was prepared by mixing 37%aqueous formaldehyde, urea and water (in amounts that constitute 30%,15% and 55% respectively), adjusting the pH to 3.0 with phosphoric acid,stirring for 2.5 hours at 25°-35° C., neutralizing with 30% aqueousammonium hydroxide, filtering and drying in a forced air oven at 40°-50°C. The slow release herbicide particulate released 23% of the activecompound in 17 hours, 59% in 136 hours and 79% in 376 hours.

EXAMPLE 5

Following the teaching of Example 1, controlled release particulate wasprepared comprising 0.5 g methyl2-[[[[[4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]methyl]benzoate(Compound II), 0.2 g of a 3:1 w:w blend of paraffin wax and Elvax® 210and 5.0 g calcium carbonate. The product contained 8.11% of Compound II,the slow release particulate prepared and released 20% of the activecompound in 18 hours; 62% in 102 hours and 81% after 449 hours.

EXAMPLE 6

Following the process of Example 5, controlled release Compound IIhaving a relatively broad range of release in about 430 hours wasobtained by incorporating magnesium hydroxide in the matrix. Thus, amixture was made of 0.5 g Compound II, 0.8 g of a 3:1 blend of paraffinwax and Elvax® 210 0.2 g magnesium hydroxide and 4.8 g calciumcarbonate. The mixture contained 7.59% active compound. The productrelease 16% of the active compound in 17 hours, 50% in 186 hours and 79%in 498 hours.

EXAMPLE 7

Using the procedure of Example 6, except substituting stearic acid formagnesium hydroxide, the following slower release pattern was observed:9% of the active compound in 66 hours, 17% in 17 hours and 27% in 402hours. This also showed that the rate of release could be adjusted bychoice of adjuvants.

EXAMPLE 8

Using the process of Example 6 except substituting salicylic acid formagnesium hydroxide, faster release was observed. The product released22% of the active compound in 66 hours and 75% in 402 hours.

EXAMPLE 9

This example relates to the formulation of granules containing twocomplimentary sulfonylureas, Compound II and Compound I for providingcontrol of a broader range of weeds than either one alone. A mixture wasmade of 5.27 g methyl2-[[[[[4,6-dimethoxy-2-pyrimidinyl)-amino]carbonyl]amino]sulfonyl]methyl]benzoateLondax® 60DF premix, and 2.0 g of the controlled release particulate ofExample 1. To this was mixed in 1.14 g of water, and the resultant dampparticulate mixture was forced through a 20 mesh screen. The resultantwet granules were dried in a forced air oven overnight at 40°-50° C. togive 600-750 granules containing 1.5% Compound I and 43.5% Compound II.The granular product released all of Compound II and 40% of Compound Iin 17 hours.

What is claimed is:
 1. A slow release herbicidal particulate compositionfor use in paddy rice comprising(1) One or more active ingredientsselected from the group:(i)N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-1-methyl-4-(2-methyl-2H-tetrazole-5-yl)-1H-pyrazole-5-sulfonamide[Compound I]; (ii) methyl2-[[[[[4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]methyl]benzoate[Compound II or bensulfuronmethyl herbicide]; and (iii) ethyl5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-amino]sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate[Compound III]; (2) paraffin wax; and (3) synthetic or naturallyoccurring hydrocarbon polymer(s); and (4) a solid particulatefiller;wherein the weight ratio of paraffin wax: hydrocarbon polymerranges from 5:1 to 0.5:1; the weight ratio of active ingredient(s):paraffin wax and hydrocarbon polymer ranges from 1:25 to 1:0.25 and thesolid particulate filler ranges from 1 to 95% by weight of the totalcomposition.
 2. Compositions of claim 1 wherein the paraffinwax:hydrocarbon polymer ranges from 4:1 to 0.5:1.
 3. The compositions ofclaim 2 wherein the active ingredients: paraffin wax and hydrocarbonpolymer ranges from 1:10 to 1:1.5.
 4. The compositions of claim 3wherein the hydrocarbon polymer is a ethylene and vinylacetate copolymeror oxidized polyethylene.
 5. The compositions of claim 4 wherein inaddition a surfactant is included.
 6. The compositions of claim 5wherein the filler is calcium carbonate.
 7. A process for preparing aslow release herbicidal composition comprising mixing:(1) Activeingredients selected from:(i)N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-1-methyl-4-(2-methyl-2H-tetrazole-5-yl)-1H-pyrazole-5-sulfonamide[Compound I]; (ii) methyl2-[[[[[4,6-dimethoxy-2-pyrimidinyl)amino]-carbonyl]amino]sulfonyl]methyl]benzoate[Compound II or Londax® herbicide]; and (iii) ethyl5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-amino]sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate[Compound III]; (2) paraffin wax; and (3) synthetic or naturallyoccurring hydrocarbon polymer(s); (4) a solid particulate filler;whereinthe weight ratio of paraffin wax: hydrocarbon polymer ranges from 5:1 to0.5:1; the weight ratio of active ingredient(s): paraffin wax andhydrocarbon polymer ranges from 1:25 to 1:0.25, heating the mixture to60°-120° C., adding the solid particulate filler in an amount thatranges from 1 to 95% by weight of the total composition and then coolingwith agitation until the temperature reaches room temperature.